Low Oil Pressure Switch Location

[TheClient]

17 hours ago, vRSRutty said:

 

According to the garage, it's actually low pressure, it was tested with a mechanical gauge which I presume bypassed and electrics, specifically the oil pressure switch.

Yeah but.... I think that IS the very first test the new garage needs to repeat with a manual gauge and see if they can replicate the low oil pressure on measurment.

 

At the moment, we don't know how they tested, where they tested on the engine, what RPM...... dare I say it, even if they tested..... I don't like to doubt people or garages but the response from your former garage was ....... pretty poor.

 

Edit: I'm assuming also - that there is a pressure problem but....... needs to be proven from somewhere you trust first......

Edited 29 November, 2023 by TheClient

[J.R.]

100% agree with your sentiments.

 

If the piston cooling jet solenoid is stuck open, it may even be its fail safe mode, then the low pressure output of the oil pump would be much lower than the specification.

[vRSRutty]

Probably the final update!

 

The garage called me a few minutes ago, and they were 100% times more helpful.

 

They've tested the pressure and it validates what the prior garage said.

 

Unfortunately, the oil pump has been replaced (shortly) before my ownership, they then dropped the sump and it looks fine, the pick-up pipe is clear and they've replaced the filter housing tensioner as well as the oil but to no avail. The car still produces the malfunction code etc.

 

He said that when he took it out for a drive and letting off the throttle at high revs, the car produces blue-ish smoke for about 15-20s after. He believes it could be a deeper issue involving the piston rings or the turbo in either case will be very costly. He said he could replace the solenoid, but with the blue smoke, the chances are very unlikely it'll have an effect.

 

So as it stands - I'm looking at an engine and/or turbo rebuild. I don't think it's a cost-efficient move to continue further sadly.

[TheClient]

2 hours ago, vRSRutty said:

Probably the final update!

 

The garage called me a few minutes ago, and they were 100% times more helpful.

 

They've tested the pressure and it validates what the prior garage said.

 

Unfortunately, the oil pump has been replaced (shortly) before my ownership, they then dropped the sump and it looks fine, the pick-up pipe is clear and they've replaced the filter housing tensioner as well as the oil but to no avail. The car still produces the malfunction code etc.

 

He said that when he took it out for a drive and letting off the throttle at high revs, the car produces blue-ish smoke for about 15-20s after. He believes it could be a deeper issue involving the piston rings or the turbo in either case will be very costly. He said he could replace the solenoid, but with the blue smoke, the chances are very unlikely it'll have an effect.

 

So as it stands - I'm looking at an engine and/or turbo rebuild. I don't think it's a cost-efficient move to continue further sadly.

Thanks for the update. 

 

Sadly, seems like bad news. 😢 

 

I'm not sure if the bluesmoke is a red herring at this stage, at least in part. Maybe.... A bad pcv can cause that on the overrun. fairly common on this platform. Could be a turbo I suppose, as a consequence of the low oil pressuere - it is passing oil. But it would usually be very noticeable I would of thought it could be worth ruling that in or out (turbo damage) by inspecting.

 

Could be rings - but I've not heard of a lot of those failures on gen 3s.

 

So the oil pressure issue, is out of spec at 0.4bar as per previous garage? is it only at idle,? Does it normalise with a few revs? Did they elaborate at all?

 

They didn't think it worthwhile replacing the oil pump because it has already been done, probably chasing same issue by previous owner? Is that the logic.  Could it be faulty? -  probably not assuming  the car had this fault before it was replaced.... but we don't know for sure. Seems likely though...

 

I would of thought you'd notice a significant oil burning problem though by needing to add oil? Which leads me to think it could be pcv or even valve stem seals.... I have heard of those needed doing on gen 3s... but the route cause of oil pressure problem remains.... 

 

 

[vRSRutty]

18 minutes ago, TheClient said:

Thanks for the update. 

 

Sadly, seems like bad news. 😢 

 

I'm not sure if the bluesmoke is a red herring at this stage, at least in part. Maybe.... A bad pcv can cause that on the overrun. fairly common on this platform. Could be a turbo I suppose, as a consequence of the low oil pressuere - it is passing oil. But it would usually be very noticeable I would of thought it could be worth ruling that in or out (turbo damage) by inspecting.

 

Could be rings - but I've not heard of a lot of those failures on gen 3s.

 

So the oil pressure issue, is out of spec at 0.4bar as per previous garage? is it only at idle,? Does it normalise with a few revs? Did they elaborate at all?

 

They didn't think it worthwhile replacing the oil pump because it has already been done, probably chasing same issue by previous owner? Is that the logic.  Could it be faulty? -  probably not assuming  the car had this fault before it was replaced.... but we don't know for sure. Seems likely though...

 

I would of thought you'd notice a significant oil burning problem though by needing to add oil? Which leads me to think it could be pcv or even valve stem seals.... I have heard of those needed doing on gen 3s... but the route cause of oil pressure problem remains.... 

 

 

 

Correct with the oil pressure, 0.4 bar idle and then normalizes and drops off with throttle.

 

The oil pump was visibly newer, presumably replaced just before being sold to me in hopes to fix but then failed to fix etc etc, could be faulty but wouldn't know unless I'm willing to pay £500 or so to have it done, which at this point, I'm not.

 

I haven't had it long enough to notice major oil consumption, it goes through some, but where I haven't been able to use much power I presume I haven't burnt through much either.

 

Not sure if the PCV was checked, after briefly checking the workshop manual I can't see any reference either.

 

Browsing another thread here, a user says a Skoda tech said it's easy to DIY(?)

 

Once the car is back, again, I'll have a little nose around.

 

EDIT: After watching a few vids, seems super easy, worth 1 final shot?

 

 

Edited 1 December, 2023 by vRSRutty

[TheClient]

35 minutes ago, vRSRutty said:

 

Correct with the oil pressure, 0.4 bar idle and then normalizes and drops off with throttle.

 

The oil pump was visibly newer, presumably replaced just before being sold to me in hopes to fix but then failed to fix etc etc, could be faulty but wouldn't know unless I'm willing to pay £500 or so to have it done, which at this point, I'm not.

 

I haven't had it long enough to notice major oil consumption, it goes through some, but where I haven't been able to use much power I presume I haven't burnt through much either.

 

Not sure if the PCV was checked, after briefly checking the workshop manual I can't see any reference either.

 

Browsing another thread here, a user says a Skoda tech said it's easy to DIY(?)

 

Once the car is back, again, I'll have a little nose around.

 

EDIT: After watching a few vids, seems super easy, worth 1 final shot?

 

 

To me it sound like the oil pump is faulty;  but I could not guarantee it.  And with it having been replaced before - makes it suspicious that someone else thought so…..

 

the pcv is also a fine oil separator. Sits on top of engine valve cover. Easy enough to replace but they are about £100 and it will not resolve low oil pressure but could solve the smoke….

 

[vRSRutty]

5 minutes ago, TheClient said:

To me it sound like the oil pump is faulty;  but I could not guarantee it.  And with it having been replaced before - makes it suspicious that someone else thought so…..

 

the pcv is also a fine oil separator. Sits on top of engine valve cover. Easy enough to replace but they are about £100 and it will not resolve low oil pressure but could solve the smoke….

 

 

Ah okay, that's a shame then. 

 

Are you suggesting the replacement part could be faulty?

[J.R.]

Worn piston rings will have zero effect on oil pressure, if they are indeed worn (does the vehicle have a thirst for oil?) then that will have an economic bearing on whether you spend more money or sell the vehicle on.

 

Vehicles like this get sold on and on through the trade each time causing grief to another retail punter who throws it back, eventually they get to someone like myself who likes a challenge and to buy cheap. I nearly always see similar evidence of the parts cannon being fired with the customers money and the solution every time to date touch wood has been either low cost or no cost.

 

My gut feeling is that the piston ring jets are in constant operation through a stuck valve or wiring fault, it could also be a missing flow restrictor to the valve gear or the wrong gasket used, maybe a seal missing on the oil pump.

 

Did they or you check the O rings on the oil filter centre spigot? That sounded like a strong possibility.

[vRSRutty]

1 minute ago, J.R. said:

Worn piston rings will have zero effect on oil pressure, if they are indeed worn (does the vehicle have a thirst for oil?) then that will have an economic bearing on whether you spend more money or sell the vehicle on.

 

Vehicles like this get sold on and on through the trade each time causing grief to another retail punter who throws it back, eventually they get to someone like myself who likes a challenge and to buy cheap. I nearly always see similar evidence of the parts cannon being fired with the customers money and the solution every time to date touch wood has been either low cost or no cost.

 

My gut feeling is that the piston ring jets are in constant operation through a stuck valve or wiring fault, it could also be a missing flow restrictor to the valve gear or the wrong gasket used, maybe a seal missing on the oil pump.

 

Did they or you check the O rings on the oil filter centre spigot? That sounded like a strong possibility.

 

No, but they replaced the tensioner, so I assume they'd have seen/checked.

 

I will check once it's back with me.

 

Even if that was the case, would that cause blue smoke?

 

 

[J.R.]

Blue smoke is a red herring, it has nothing to do with oil pressure loss.

[vRSRutty]

1 minute ago, J.R. said:

Blue smoke is a red herring, it has nothing to do with oil pressure loss.

Got it, he did say that's a possibility.

 

I really want to get to the bottom of it, but I haven't got the skill set to check, and the labour cost to check those is something I can't really afford on an off chance it might fix it.

 

Every garage has stressed the amount of hours it'll take to replace the pump, I assume it'll be similar to check it's all in working order.

 

And then when it comes to piston ring jets - that sounds extremely expensive.

[TheClient]

13 hours ago, vRSRutty said:

Got it, he did say that's a possibility.

 

I really want to get to the bottom of it, but I haven't got the skill set to check, and the labour cost to check those is something I can't really afford on an off chance it might fix it.

 

Every garage has stressed the amount of hours it'll take to replace the pump, I assume it'll be similar to check it's all in working order.

 

And then when it comes to piston ring jets - that sounds extremely expensive.

It is hard when it gets to the point you're at - with issues confirmed by a second garage, but no obvious resolution path and then to need to pay a garage for any further investigation work or repairs knowing that:

 

i) there may be an oil burning issue (but maybe fixable, maybe not serious)

ii) there is an oil pressure issue

iii) the possibility of engine damage. (seems less likely if the overhead gear sounds ok, engine running ok and the pressure is only an issue at idle but still a possibility)..

 

You have to weigh all this up...

 

@J.R. makes some suggestions including looking at the oil pump assembly and suggesting the piston cooling jet circuit could be stuck open. This is the deenergised state of the cooling jet control valve n522.

 

I'm less convinced the piston cooling jet circuit is the problem (but never say 100% sure). It is designed to operate in both low and high pressure pump stages. So even if it was on all the time (as would be the case in a de-energised state of the control valve) then it still should not produce out of spec oil pressure by design. (edit: although, in operation, given trigger parameters - would it ever be called at for idle at, so maybe could produce out of spec.....) Only way to confirm is to test at L3 location with gauge or test on another car by removing the connector to the control valve whilst monitoring oil pressure with gauge.....

 

If you had time, you could confirm the cooling jet operation is turning off by checking pressure at the the level 3 switch during idle low revs. But the ECU is supposed to produce a fault as well for delivering pressure to the circuit when not requested  in addition to not delivering pressure when requested. So the control jet valve and the L3 switch would have to be faulty for that circumstance as well.   You could remove the control valve in the oil filter bracket near the oil pressure switches and clean it... edit. You could replace the control valve speculatively - they are under £100 from recall...

 

It would be interesting to see what the oil pressure was on the engine with a gauage with the N428 disconnected and removed (an earlier suggestion for the mechanic).

 

That would run the oil pump in high pressure mode all the time. It could also provide a sticking plaster for the problem by clearing the low pressure issue. You would need to permanently delete out / recode the oil control valve open circuit fault from re-appearing somehow which according to one of the other posts I linked, can be done, and has been done by someone else and the car continue to be driven..

 

When you say the oil pump has been replaced recently is new, are you saying it looks like it has been out and cleaned up or are you saying the part number on it shows a revision of recent manufacture later than the car?

 

Because, depending on which, the conclusion that it has been replaced could be wrong. Personally, I'm thinking the pump could be faulty or installed wrongly but as I have said before, I could not guarantee it and it is worrying it has had attention before. It is not a cheap part but also is not £1000s. Maybe a second hand pump could be sourced - although you would never know its condition. 

 

Sorry, no easy fixes left I don't think.. And no guaranteed next step fixes either.

 

How many miles on the car, you may have said but this thread is a lot of posts now?

Edited 2 December, 2023 by TheClient

[J.R.]

100% with you on the questioning of whether the oil pump is actually new, even if he does now have a garage who doesn't make stuff up there can be misunderstandings, we are not dealing with the horses mouth.

 

My suggestion of the N428 valve being suck open came from reading the self study guide you posted, I am sure it said the piston cooling was only activated on the high pressure pump operation, I think that may be a dodgy translated term as I think the pump switches between high and low flow rate (are there 2 pressure relief valves?). I dont have time to read it through again and in any case I get the impression that the OP will not be funding the fault finding any further, disconnecting the valve is something that he can do without cost.

 

It will be a shame to see him lose the vehicle and money knowing that someone else will get stitched up with the problem just as they did, resolution has to be the best outcome.

[vRSRutty]

3 hours ago, TheClient said:

It is hard when it gets to the point you're at - with issues confirmed by a second garage, but no obvious resolution path and then to need to pay a garage for any further investigation work or repairs knowing that:

 

i) there may be an oil burning issue (but maybe fixable, maybe not serious)

ii) there is an oil pressure issue

iii) the possibility of engine damage. (seems less likely if the overhead gear sounds ok, engine running ok and the pressure is only an issue at idle but still a possibility)..

 

You have to weigh all this up...

 

@J.R. makes some suggestions including looking at the oil pump assembly and suggesting the piston cooling jet circuit could be stuck open. This is the deenergised state of the cooling jet control valve n522.

 

I'm less convinced the piston cooling jet circuit is the problem (but never say 100% sure). It is designed to operate in both low and high pressure pump stages. So even if it was on all the time (as would be the case in a de-energised state of the control valve) then it still should not produce out of spec oil pressure by design. (edit: although, in operation, given trigger parameters - would it ever be called at for idle at, so maybe could produce out of spec.....) Only way to confirm is to test at L3 location with gauge or test on another car by removing the connector to the control valve whilst monitoring oil pressure with gauge.....

 

If you had time, you could confirm the cooling jet operation is turning off by checking pressure at the the level 3 switch during idle low revs. But the ECU is supposed to produce a fault as well for delivering pressure to the circuit when not requested  in addition to not delivering pressure when requested. So the control jet valve and the L3 switch would have to be faulty for that circumstance as well.   You could remove the control valve in the oil filter bracket near the oil pressure switches and clean it... edit. You could replace the control valve speculatively - they are under £100 from recall...

 

It would be interesting to see what the oil pressure was on the engine with a gauage with the N428 disconnected and removed (an earlier suggestion for the mechanic).

 

That would run the oil pump in high pressure mode all the time. It could also provide a sticking plaster for the problem by clearing the low pressure issue. You would need to permanently delete out / recode the oil control valve open circuit fault from re-appearing somehow which according to one of the other posts I linked, can be done, and has been done by someone else and the car continue to be driven..

 

When you say the oil pump has been replaced recently is new, are you saying it looks like it has been out and cleaned up or are you saying the part number on it shows a revision of recent manufacture later than the car?

 

Because, depending on which, the conclusion that it has been replaced could be wrong. Personally, I'm thinking the pump could be faulty or installed wrongly but as I have said before, I could not guarantee it and it is worrying it has had attention before. It is not a cheap part but also is not £1000s. Maybe a second hand pump could be sourced - although you would never know its condition. 

 

Sorry, no easy fixes left I don't think.. And no guaranteed next step fixes either.

 

How many miles on the car, you may have said but this thread is a lot of posts now?

 

The garage said it had been replaced before as it looks newer and had been replaced by a genuine part.

 

The car is at 95,000 miles.

 

@J.R. In regards to N428, I will try leaving it unplugged, and delete the error code myself, and see if there's any improvement. If there is, could be a pointer to that. 

 

I posted a thread above in which a mechanic said he unplugged it and re-coded it, and since then the car has done 20,000 miles problem free, so I deffo think it's worth a shot. 

Edited 2 December, 2023 by vRSRutty